This invention relates in general to the field of orthopedic surgery including, more specifically, the field of spinal surgery. In particular, this invention relates to an improved structure for a needle that can provide selective directional control of the injection of a bone cement or other material into a fractured bone, such as a vertebra of a spine, during a spinal surgical procedure.
A compression fracture is a common fracture of a vertebra of the spine. In a typical compression fracture, the vertebra has suffered a crush or wedging injury. Vertebral compression fractures are common, especially in older adults who suffer from osteoporosis. Traditional conservative treatment includes bed rest, pain control, and physical therapy. For those patients who do not respond to conservative treatment, interventional procedures such as kyphoplasty and vertebroplasty can be considered. During a kyphoplasty procedure, a void is created within the fractured vertebra by initially inflating a balloon therein, then injecting a bone cement material under a relatively low pressure into the void. During a vertebroplasty procedure, a relatively high viscosity bone cement material is injected directly into the fractured vertebra without the initial creation of a void by balloon inflation.
In both of these procedures, the bone cement material may be injected into the fractured vertebra using a vertebral needle that can facilitate the directional flow of bone cement material to a desired location, thus improving the fill of the bone cement material within the vertebra. Most currently available vertebral needles allow the bone cement material to be injected either only (1) axially straight through a hole provided at the tip of the vertebral needle or (2) radially sideways through a hole provided in the sidewall of the vertebral needle. Thus, to optimize the control of the flow of the bone cement material into the vertebra, both of the two known types of the vertebral needles need to be used during the course of the surgical procedure. However, the intra-operative changing of the vertebral needles is relatively difficult and time consuming. Thus, it would be desirable to provide an improved structure for a needle that can provide selective directional control of the injection of a bone cement or other material into a fractured bone, such as a vertebra of a spine, during such a spinal surgical procedure.